PROJECT SUMMARY The purpose of the proposed research is to describe and cross-nationally compare the life-course pathways affecting cognition, cognitive impairment, dementia, and cognitive decline in the United States and Mexico. The PI, Dr. Joseph Saenz, received his Ph.D. in Population Health Science at the University of Texas Medical Branch where he received training in epidemiology and epidemiologic methods. Dr. Saenz has extensive experience studying health disparities in Mexico and the Mexican origin population in the United States. Joseph is currently a postdoctoral fellow at the Davis School of Gerontology at the University of Southern California (USC) where he has begun to study cognition in these populations. The proposed training will enhance the PI?s understanding of the measurement of cognition, and expose him to the approaches to cognitive aging used across various academic disciplines including demography, psychology, neuropsychology, and biology. Education is a strong predictor of cognitive function, cognitive impairment without dementia (CIND), and dementia in late life. Education may affect the clinical manifestation of cognitive functioning directly by impacting the strength and structure of brain structures and by providing greater cognitive reserve to compensate for pathological changes in the brain. However, education may also affect cognition via indirect pathways including occupation, income, wealth, healthcare access, and chronic conditions. Understanding these pathways is highly significant given the aging of the U.S. and Mexican populations and the social and economic costs of cognitive impairment. Because aging is a life-course process that occurs within larger contexts, it is important to consider how larger demographic, economic, and political contexts across countries influence cognitive development and decline throughout the life-course. Further, by acknowledging these differing contexts, future work may design and implement cognitive interventions that are more precisely catered to the context in which they are applied. These results also shed light on differences in cognitive aging across developing and developed countries. While studies of aging in Mexico (Mexican Health and Aging Study) and the U.S. (Health and Retirement Study) have used differing measures of cognitive functioning and methods for measuring and classifying normal cognition, CIND, and dementia, the proposed research makes use of newly collected harmonized assessments of cognitive functioning to develop comparable measures of cognition and definitions of CIND and dementia. I will investigate the direct and indirect pathways throughout the life-course through which education affects cognitive functioning, CIND, dementia, and cognitive decline in late life using multinomial probit regression models, growth curve models, and linear regression models to model CIND and dementia, cognitive decline, and cognitive function as a function of variables spanning the life-course. USC is an ideal location to receive the training necessary for the proposal given the multidisciplinary nature of the gerontology center, global study of aging, focus on cognition and dementia, and availability of coursework and mentorship from leaders in demography, psychology, and clinical psychology. This training will also position the PI to begin an independent research career and to submit a successful R01 proposal in a faculty position.